1. Field of the Invention
The present invention relates generally to a navigation system, and in particular, to a data transmitting and receiving method between a mobile terminal and an information center.
2. Description of the Related Art
Typically, a navigation system displays a calculated current location of a mobile body using received information from a Global Positioning System (GPS) which is displayed in a map on a screen. Also, the navigation system provides salient driving information including moving direction of the mobile body, distance to a destination, current moving velocity of the mobile body, a path preset by the driver before driving, or an optimal path to the destination, etc. The navigation system or GPS is mounted on the mobile body including a boat, an airplane, an automobile, etc., to be used to determine current location and moving velocity of the mobile body or decide a driving path.
Recently, a navigation system has been developed for providing a navigation function via mobile terminals. FIG. 1 shows an outlined configuration of the navigation system.
Referring to FIG. 1, the navigation system comprises an information center 100, a wireless network 200, a mobile terminal 300 and an Intelligent Transport Systems (ITS) terminal 400. The information center 100 stores map data and real-time traffic information. When the mobile terminal 300 requests the navigation function, the information center 100 generates corresponding navigation information comprising map data and real-time traffic information and provides it to the mobile terminal 300 via the wireless network 200. The wireless network 200 is a path for information transfer between the information center 100 and the mobile terminal 300. The mobile terminal 300 operates not only in a typical mode for providing voice call service to a user, but it also operates in a navigation mode support for the navigation function. In the navigation mode, the mobile terminal 300 is connected to the wireless network 200, receives every kind of navigation information available and provides them to the user by interacting with the ITS terminal 400.
In the navigation mode, the user may request guidance of optimal driving path to the information center 100 by transmitting current location of his car and destination via his mobile terminal 300. Accordingly, the user can be guided to the optimal driving path between the current location and the destination, a typical navigation function, by the information center 100. In the navigation mode, the user can also connect to the information center 100 via the mobile terminal 300 and search neighboring facilities, for example, gas stations, rest areas, repair shops, hospitals/drug stores, lodging houses, sight spots, restaurants/cafés, and theaters/stages, etc.
The navigation system is mounted on the mobile body such as a car, etc., as a separate device, to provide convenient functions such as driving path to a driver. For this, the mobile terminal 300 is connected to the information center 100, sets a desired destination and receives path guiding data generated by the information center 100 via the wireless network 200.
However, there occur cases of disconnection in the middle of setting the destination or receiving the path guiding data due to the limit of data communication through the wireless network 200. For example, during passing a tunnel or due to problems in the wireless network 200 transmission/disconnect problems may occur. In those cases, the mobile terminal 300 must subsequently re-transmit the destination and download the path guiding data.
In the related art, as described above, there is inconvenience of re-transmission and down loading navigation information when the mobile terminal 300 is disconnected from the information center 100 in the middle of setting destination or receiving the path guiding data. There is an additional problem of increase of communication costs for the user due to re-downloading the same data. While reconnecting to the information center 100, the car may also have altered its course in the interim. Then the current location of the car becomes changed. Therefore, the user must download other guiding data for the changed path from the changed current location to the destination.